1. Field of the Invention
The present invention relates to an actuator using an electromechanical transducer, for example, to an actuator using an electromechanical transducer which is suitable for driving general precision mechanical devices such as driving units of an X--Y axes movable stage, a photographing lens of a camera, a projecting lens of an overhead projector, a lens of a binocular and so on and which can maintain stable driving function even in a severe environment of high temperature, high humidity or the like.
Further, the present invention relates to an apparatus mounted with such an actuator for stably operating even in a severe environment of high temperature, high humidity or the like.
2. Prior Art
In driving an X--Y axes movable stage, a photographing lens of a camera or the like, a drive device using an electric motor has conventionally been used. The device is large-sized and drawbacks of generation of a magnetic field or generation of noise or the like have been pointed out. Hence, the applicant has proposed as means for resolving such various problems an actuator using an electromechanical transducer, that is, an actuator in which a moving member is frictionally coupled to a driving member that is fixedly coupled to an electromechanical transducer and displacements in elongation and contraction directions having different speeds are generated by applying drive pulses in a sawtooth waveform to the electromechanical transducer by which the moving member frictionally coupled to the driving member is moved in a predetermined direction.
According to the above-described conventional actuator, the piezoelectric element, a portion for fixedly adhering the piezoelectric element and a support block, and a portion for fixedly adhering the piezoelectric element and a drive shaft are integrated into an apparatus where it is used without conducting any special treatment therefor. However, when the apparatus to which the actuator of this kind is applied is used in an environment of high temperature or high humidity, there is a possibility which may cause inconvenience where electrodes of the piezoelectric element are shortcircuitted, the portion for fixedly adhering the piezoelectric element and the support block or the portion for fixedly adhering the piezoelectric element and the drive shaft are peeled off, the function is deteriorated, the apparatus cannot be driven or the like. Further, when the apparatus to which the actuator of this kind is applied is left in an environment of high temperature or high humidity, there is a possibility which may cause inconvenience where similarly, the fixedly adhered portion is peeled off, the function is deteriorated, the apparatus cannot be driven or the like.